Sexual reproduction in multi-cellular organisms entails generation of meiotically competent germ cells within a somatic body. Developmental mechanisms responsible vary among taxa, however, most animals exhibit continuous production from stem cells specified during embryogenesis. In contrast, angiosperms are strictly vegetative until intrinsic and environmental cues trigger flowering. Within anther and carpel primordia, indeterminate floral progenitor cells differentiate as pre-meiotic archesporial (AR) cells and somatic parietal cells, but the morphogenetic mechanisms responsible remain unclear. The nature of the somatic to germinal switch, and the degree to which it is under developmental or physiological control, has until now been a botanical mystery.